Butterfly knife



FIG. 1 is a perspective view of a butterfly knife showing our new design;

FIG. 2 is another perspective view thereof, wherein the knife is inverted;

FIG. 3 is a front elevation view thereof;

FIG. 4 is a rear elevation view thereof;

FIG. 5 is a left side elevation view thereof;

FIG. 6 is a right side elevation view thereof;

FIG. 7 is a top plan view thereof;

FIG. 8 is a bottom plan view thereof; and,

FIG. 9 a perspective view of the butter knife in a half open position.

The contour shading lines do not represent surface indicia, but are utilized to illustrate the surface contours of the butterfly knife. Any broken line matter represent aspects of the butterfly knife that form no part of the claimed design. 

CLAIM The ornamental design for a butterfly knife, as shown and described. 